Demonstration of a technological prototype of an active‐matrix BiNem liquid‐crystal display

Abstract— The first implementation of active‐matrix addressing on a BiNem bistable nematic liquid‐crystal display has been demonstrated. Compared to previous passive‐matrix addressing, major improvements have been made for the bistable mode: a smoother image refreshment, shorter refreshing frame time compatible with that of high‐resolution e‐book displays, the use of a touch screen for interactive functions such as hand‐writing, a virtual keyboard, improved functionality for scrolling menus, partial refreshment, etc. On the same display but in the monostable mode, by using electrically controlled birefringence (ECB), the potential of displaying moving pictures at a rate of 25 images/sec, at an extended room temperature, has been demonstrated. In the ECB monostable mode, static images can be displayed down to ?20°C. A new transflective single‐polarizer optical mode has been developed to optimize the indoor and outdoor readability of the display. By lowering the surface reflection and enhancing the panel transmission, a contrast ratio of 94:1 and a transmittance of 17% have been achieved.     

LED PWM dimming linearity investigation

LED PWM dimming application for large scale LED video displays is analyzed. The need for short light pulse duration is outlined. PWM dimming with short driving pulses is investigated experimentally. The LED response time skew introduces the nonlinearity for PWM dimming. For LED response time skew estimation, a method is suggested that has been successfully applied to measure some of today’s market representative LEDs. PWM dimming nonlinearity can be forecasted using the estimated skew. For a particular driving configuration, it is indicated that LED PWM dimming fails to satisfy the required 14 bit output coding together with the image refresh frequency of 400 Hz. A rough investigation demonstrates that the skew is quite stable. Therefore, the nonlinearity correction for the PWM pulse durations shorter than the skew value should be possible.     

Measuring 3D crosstalk uniformity and its influence on contrast ratio

An array detector was employed to characterize the crosstalk and contrast ratio uniformity of three‐dimensional (3D) displays. The measurement method is described and demonstrated on a stereoscopic display with passive glasses. The resulting high resolution spatial uniformity maps enable a comprehensive statistical characterization of the display and provide a useful visual assessment tool. The statistical uniformity data are used to evaluate the crosstalk dependence on viewing conditions (such as viewing distance), and show the degradation in display performance that could not be captured with a discrete spot measurement. The measurement method was also employed to examine the influence of crosstalk on contrast ratio. It is shown that for some 3D displays, the crosstalk uniformity can dominate the perceived contrast. A metric is proposed that defines the maximal crosstalk contribution to the perceived contrast for 3D images with small features. The summary parameters extracted from the uniformity maps can be utilized to define the boundary viewing conditions needed to maintain minimum image quality.     

A practical guide to flicker measurement: using the flicker-matching technique

We have developed an empirical technique for measuring perceived flicker on refresh displays. This technique is based in vision science, is technology independent and has proved to be a useful tool in display development and product assurance. It has been used to evaluate a large number of displays varying in size, luminance, refresh rate, phosphor decay and colour. In this paper we describe the flicker-matching technique (FMT) and provide detailed information on its operation. In the IBM flicker-matching technique, observers of known flicker sensitivity compare the amount of flicker on the display to the amount of flicker on a standard light. The temporal frequency of the standard light is then varied until the display and light appear to flicker equally. We measure this 'matching frequency' at three levels of display contrast. In the 'standard test' version of this technique, we distil a figure of merit for each display based on the performance of observers in the top 5 per cent of the population. This figure of merit corresponds well with field reports and success in receiving a 'safety label' from the German TCA (Berufsgenossenschaft).     

Contrast‐enhanced wide‐angle high‐speed polarization modulator for active‐retarder 3‐D displays

Abstract— A contrast‐enhanced wide‐angle high‐speed polarization modulator for active‐retarder 3‐D displays is proposed. By using a double liquid‐crystal‐cell structure together with a dedicated driving scheme and an external quarter‐wave retarder, a high‐performance modulator can be realized, resulting in minimized brightness loss and low cross‐talk levels in fast‐refresh time‐multiplexed 3‐D displays.     

Correlation modelling of reaction time for two- and three-dimensional stimulus–response arrangements

Research on the effects of the spatial correlation between signal and response key has shown a clear relationship between signal/response spatial correlation and reaction time (RT) for signals and response keys that are in a linear relationship (Morin and Grant 1955; Hoffmann 2010). By means of a reanalysis of previous data of Chan and Chan (2009a, 2009b, 2011a, 2011b, 2010), the equivalent relationships for two-dimensional (2D) and three-dimensional (3D) display/control relationships are established. In a 2D array of signals with a corresponding 2D array of response keys, RT is dependent on spatial correlation, with arrangements having transverse compatibility reacting faster than those with longitudinal compatibility. 3D arrangements show a similar effect, with up/down compatibility being a major factor in determination of RT and with similar effects of transverse compatibility. The results indicate the best arrangements of signal/key arrangements where complex designs are necessary.

Practitioner Summary: Design of complex display/control arrangements requires high compatibility in order to minimise reaction times. This work extends previous research to cases where displays and controls are in two-dimensional and three-dimensional arrangements, and indicates how reaction time is affected by these more complex arrangements.     

Video game playing in the general adult population of Germany: Can higher gaming time of males be explained by gender specific genre preferences?

BackgroundPrior studies observed involvement with video games to vary between different sociodemographic strata with considerable higher gaming time in males compared to females. However, empirical evidence explaining the gender gap in gaming time is still scarce. The present study aims to evaluate if the higher gaming time can be attributed to gender specific game genre preferences.MethodsA nationwide representative survey comprising 3073 participants aged 16–93 years (M = 49.1; SD = 18.2) was conducted. Video game use and genre preferences were assessed via a written questionnaire. OLS regression and subsequent mediation analyses were used to determine significant predictors of gaming time and to evaluate the contribution of genre preferences.ResultsHigher age, high education and employment predicted lower gaming time whereas male gender and the preference of certain game genres predicted higher gaming time. Mediation analyses revealed that the higher gaming time of males is fully mediated by the higher preference of role-playing and shooter games among this gender group.ConclusionThe higher gaming time of men is fully accounted for by the male specific preference for certain game genres. Future research should address the functional connection between genre preferences and gaming behavior in further detail.     

The explicit and implicit outcome expectancies of Internet games and their relationships with Internet gaming behaviors among college students

Although previous research has noted that outcome expectancies have played an important role in young people’s risk-taking behaviors, few studies have focused on the characteristics of Internet gaming outcome expectancies and their relationships with college students’ Internet gaming behaviors. This study combined self-report questionnaires and the go/no-go association task in examining the characteristics of the explicit and implicit Internet gaming outcome expectancies of 64 college students and their relationships with Internet gaming behaviors. The results indicated that Internet gaming-addicted college students explicitly reported more negative Internet gaming outcome expectancies than positive Internet outcome expectancies, while they unconsciously associated Internet games with positive and negative outcomes simultaneously in daily life. In contrast, the non-addicted group reported a neutral attribute toward Internet gaming outcome expectancies, while they implicitly associated Internet games more with negative outcomes than with positive outcomes in daily life. Moreover, explicit and implicit outcome expectancies did not exhibit significant correlations. Explicit outcome expectancies were correlated with present levels of addiction and indulgence, whereas implicit outcome expectancies were related to the length of time that an individual maintained Internet gaming behavior. Our findings have clinical implications. The findings can be applied to the diagnosing and intervention of Internet gaming addicts.     

High-resolution gaming: Interfaces,notifications, and the user experience

Advances in technology and display hardware have allowed the resolution of monitors – and video games – to incrementally improve over the past three decades. However, little research has been done in preparation for the resolutions that will be available in the future if this trend continues. We developed a number of display prototypes to explore the different aspects of gaming on large, high-resolution displays.By running a series of experiments, we were not only able to evaluate the benefits of these displays for gaming, but also identify potential user interface and hardware issues that can arise. Building on these results, various interface designs were developed to better notify the user of passive and critical game information as well as to overcome difficulties with mouse-based interaction on these displays. Different display form factors and user input devices are also explored in order to determine how they can further enhance the gaming experience. In many cases, the new techniques can be applied to single-monitor games and solve the same problems in real-world, high-resolution applications.     

Transmission and reflection dual operational mode MEMS display device

A novel MEMS display device comprising a light separator and MEMS light shutters is introduced. This device is operable both in transmissive mode using internal light source and in reflective mode using external sun light. In transmissive mode, the light separator directs internal backlight illuminated on its incident surface into a plural of small openings (grooves) on the viewing surface. The MEMS light shutters are used to control the color and intensity of light at individual pixels. Internal light utilization efficiency of this display is the greatest compared to any other transmissive displays. The device is capable of having true black background, hence a very high contrast ratio. In reflective mode, MEMS shutters direct part of the sun light for image display. MEMS shutters have fast response time, making the new device suitable for vivid motion picture display, and operable at very low voltages, suitable for mobile device applications.     

Spatial optical modulator (SOM): Samsung's light modulator for next‐generation laser displays

Abstract— A new type of diffractive spatial optical modulators (SOMs) has been developed for projection‐display and other applications such as holographic data storage, programmable lithography, and optical communications. It exhibits the inherent advantages of fast response time and high‐performance light modulation, suitable for high‐quality and high‐resolution projection displays. The ±1st‐order efficiency and contrast ratio of 39% and 1000:1 was achieved for a prototype SOM. The response time can be as fast as 0.7μsec with a 400‐nm displacement, enough to make a full‐HD display, being driven by 10‐V. A laser display in full‐HD format (1920 × 1080) was successfully demonstrated by using prototype projection engines having SOM devices, signal‐processing circuits, and projection optics.     

Comparison of organic and inorganic alignment layers for low‐power liquid‐crystal devices using low‐frequency applied‐voltage waveforms

Abstract— Bistable displays are known to have low‐power consumption, but they usually lack the ability to display full‐color video‐rate images. Operating active‐matrix liquid‐crystal displays (AMLCDs) with an ultra‐wide refresh‐rate range, down to ～1 Hz, can lower the power consumption to that of bistable devices and offer video rates as well. A SiO^x‐layer‐based liquid‐crystal (LC) alignment technique is studied here to overcome the ion problems typically encountered with low‐refresh‐rate devices. The effect of ions on the voltage‐holding ratio (VHR) and residual DC voltage (RDC) with SiO^x‐based LC alignment is compared with those for polyimide‐based LC alignment. It is found that only SiO^x alignment provides high VHR and small RDC, with good stability over time. Therefore, it is shown that SiO^x alignment is an excellent candidate for low‐power AMLCDs operated with an ultra‐wide refresh‐rate range.     

Discomfort and visual displays

The complaints of discomfort associated with the use of cathode ray tube displays are discussed from the perspective of a recent neurological theory of visual discomfort. It is concluded that stripes with a certain width, spacing and contrast can induce discomfort and various visual effects. Care should be taken with CRT display designs because such discomfort can be induced by a combination of the refresh rate and the ‘strioes’ formed by the lines of test. The difference in reading speeds between CRT displays and printed text is also discussed.     

Gaming addiction,definition and measurement: A large-scale empirical study

Although the general public appears to have embraced the term ‘videogame addiction’, the scientific debate as to whether ‘gaming addiction’ can actually be considered an addiction similar to substance addictions of DSM-IV is still unsettled. To date, research on gaming addiction has focused on problematic behavior from the gaming activity itself and there has been little empirical research related to pathological personality patterns that usually are associated with substance addictions. Therefore, the current study examined how game exposure and ‘problematic gaming behavior’ are related to personality patterns associated with addiction by means of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2). A large-scale survey study was performed among 1004 adolescent boys (age-range 11–18, M = 14.18, SD = 1.36) measuring problematic gaming behavior, physical game-related symptoms, gaming behavior and three MMPI-2 subscales measuring personality patterns usually associated with substance addiction (MAC-R, APS, AAS). Results showed that problematic gaming and physical symptoms were positively related to all MMPI-2 subscales, while game exposure was not related to the indirect measures of addictive personality patterns (i.e., MAC-R, APS). Thus, problematic gaming should be clearly distinguished from high game exposure. High game exposure merely indicates enthusiasm for some although it may be psychopathological for others.     

基于Nano-X的视频监控OSD设计与实现

针对嵌入式视频监控系统的图形用户界面(GUI)应具有存储空间小、实时性高的要求,提出一种基于Nano-X的实时视频监控在屏显示(OSD)设计方案。以PowerPC处理器和TI DSP为硬件平台,对Microwindows进行移植和裁剪。采用直接存储器存取方式进行OSD数据的PCI总线传输,判断变动区域实现GUI局部数据的刷新,通过DM6467的VDCE硬件模块进行鼠标图层叠加,以此提高系统的实时性。实验测试结果表明,该系统中单帧OSD数据的最大处理时间低于37.98 ms,鼠标叠层时间降至13.6 ms以下,有效地达到了25 f/s的实时刷屏要求。     

Design of carbon nanotubes for large‐area electron field‐emission cathodes

Abstract— Electron field‐emission displays offer a viable option for the next generation of flat‐panel screens. Boasting high‐quality images in terms of good color saturation, fast refresh rate, and high brightness, these displays have the potential to offer above and beyond what the current market leaders, LCD and plasma. However, for the realization of such a new display disrupting the incumbent LCD and plasma displays, not only does the image quality need to be better, but fabrication costs and suitable manufacturing processes need to be in place at reduced cost. Many viable cathode materials have been proposed in recent years, one of which being the use of carbon nanotubes (CNTs) in various forms (aligned growth, screen printing, and polymer matrix). In this review, a series of recent experiments investigating the field‐emission characteristics of carbon‐nanotube systems for possible use in the display industry is presented.     

A novel spectrum‐sequential display design with a wide color gamut and reduced color breakup

Abstract— The advantage of RGB color‐sequential displays is that they have no color filters, but the disadvantage is that they need to run at high refresh rates (> >180 Hz) to prevent flicker and color breakup. An alternative color‐sequential display, which can operate at relatively low refresh rates (～ 100 Hz) without disturbing color breakup or flicker, has been developed. The display has two color filters per pixel (cyan and magenta) on the LCD panel and the backlight can generate two types of spectra (blue‐green and green‐red), which results in a wide gamut four‐primary display, effectively. One part of the paper describes the color reproduction, including color‐filter design, gamut mapping, and multi‐primary conversion. The other part deals with the reduced perception of color breakup on the novel spectrum‐sequential display compared to conventional color‐sequential displays.     

Interactive gaming reduces experimental pain with or without a head mounted display

While virtual reality environments have been shown to reduce pain, the precise mechanism that produces the pain attenuating effect has not been established. It has been suggested that it may be the ability to command attentional resources with the use of head mounted displays (HMDs) or the interactivity of the environment. Two experiments compared participants’ pain ratings to high and low levels of electrical stimulation while engaging in interactive gaming with an HMD. In the first, gaming with the HMD was compared to a positive emotion induction condition; and in the second experiment the HMD was compared to a condition in which the game was projected onto a wall. Interactive gaming significantly reduced numerical ratings of painful stimuli when compared to the baseline and affect condition. However, when the two gaming conditions were directly compared, they equally reduced participants’ pain ratings. These data are consistent with past research showing that interactive gaming can attenuate experimentally induced pain and its effects are comparable whether presented in a head mounted display or projected on a wall.     

Nematic liquid‐crystal technology for Si wafer‐based reflective spatial light modulators

Various nematic LC modes are reviewed and compared in terms optical throughput, driving voltage, response time, contrast ratio, and spectral responses for LCoS applications. The effects of fringe‐field‐induced disclination on display performance and the mechanism of slow response of the disclination line between two topologically non‐equivalent LC states will be discussed. Issues involving flicker and photo‐instability of LCoS displays will be addressed as well.     

Laptop displays performance: Compliance assessment with visual ergonomics requirements

The use of display devices such as smartphones, tablets, laptops is now massive and continuous in everyday life. It, therefore, becomes increasingly important to be aware of the performance of these devices, not only in terms of the tasks to be performed but also in terms of interaction with humans and therefore knows any possible effect on the ergonomics of vision. Following previous research activities conducted by the authors on the assessment of the visual ergonomics at video display terminal workstations, the aim of this study is to evaluate the ergonomics of human-system interaction of laptop displays. In details, a sample of 57 laptop displays is analyzed in accordance with the requirements of the EN ISO 9241-3xx series of international standards related to the display luminance, luminance ratio, contrast non-uniformity. An extensive luminance measurement campaign was carried out using a special pattern that allowed to measure the luminance in 13 different areas of the displays. The results obtained with this activity showed a great luminance variability between different displays. Almost all the displays are able to emit high levels of display luminance, and almost all the displays meet the requirement of contrast non-uniformity. However, several devices did not meet the recommended values of luminance ratio. Furthermore, the authors created a simplified graph to allow a rapid evaluation of the performance of the displays. This method could be periodically used in practice in order to evaluate the residual performance level.