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Luminescent nanomaterials are used in everyday life due to their employment in distinct fields of science and technology, like cathode ray tubes (CRTs), flat panel display devices, temperature sensors, lasers, solar-cells, biological imaging, and solid-state lighting but also as carriers for miscellaneous therapeutic drugs. We have prepared dysprosium Dy3+ (0.5 mol %) doped lanthanum phosphate (LaPO4) phosphor by solid state reaction method. The excitation spectra of synthesized phosphor at 595 nm monitoring were composed of broadband and a series of sharp peaks, the strongest excitation peak at 254, 271, and 350 nm. The main emission spectra of samples under 254, 271, and 350 nm excitation are Dy3+ (0.5 mol %) doped LaPO4 phosphor observed at 477 and 573 nm corresponding to blue and yellow color. The broadband emission is the characteristic of the allowed f-h transition of Dy3+ ions. The corresponding emission band is observed due to the (blue emission) 4f9/2→6h15/2, (yellow emission) 4f9/2→6h13/2 transition of Dy3+ ions. All the samples have been characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and photoluminescence (PL) techniques. [ABSTRACT FROM AUTHOR]

The growing generation of waste electrical and electronic equipment (WEEE) in developing countries has attracted increasing attention due to its potential health and environmental impacts and high recycling potentials. For example, along with the rapid economic development, China has been experiencing a sharp increase in the production and use of TV sets and a quick transition from old fashion cathode ray tube (CRT) ones to flat panel display (FPT) ones. Understanding such dynamics would be important for predicting future WEEE generation. In this article, we developed a dynamic (from 1992 to 2040), bottom-up (TV sets by module by material), and stock-driven (using future possession as a driver) material flow analysis model to investigate the amount of metals and plastics embodied in obsolete TV sets in the future. We found that the total generation of obsolete TV sets in China will reach 142 million units by 2040, in which FPD TV sets contribute more after they started to dominate the market after 2009. These growing obsolete TV sets would mean potentially large amount of embodied materials that can be recycled. While most of the embodied precious metals (e.g., gold, silver, and palladium), common metals (e.g., iron, aluminum, zinc, and tin), toxic metals (e.g., mercury, barium, and antimony), and plastics will increase in future, copper and nickel show a first decrease then increase trend, and lead will be gradually phased out in obsolete TV sets. Our results could help inform waste management and recycling strategies and relevant decision makers (e.g., governmental agencies, manufactures, and recyclers) in the TV sets sector in China. Such a stock-driven and bottom-up approach can also be used for other e-waste issues and other countries. [ABSTRACT FROM AUTHOR]

Because of the rapid succession of technological developments, the architecture and material composition of many products used in daily life have drastically changed over the last decades. As a result, well-adjusted recycling technologies need to be developed and installed to cope with these evolutions. This is essential to guarantee continued access to materials and to reduce the ecological impact of our material consumption. However, limited information is currently available on the material composition of arising waste streams and even less on how these waste streams will evolve. Therefore, this paper presents a methodology to forecast trends in the material composition of waste streams. To demonstrate the applicability and value of the proposed methodology, it is applied to forecast the evolution of plastic housing waste from flat panel display (FPD) TVs, FPD monitors, cathode ray tube (CRT) TVs and CRT monitors. The results of the presented forecasts indicate that a wide variety of plastic types and additives, such as flame retardants, are found in housings of similar products. The presented case study demonstrates that the proposed methodology allows the identification of trends in the evolution of the material composition of waste streams. In addition, it is demonstrated that the recycling sector will need to adapt its processes to deal with the increasing complexity of plastics of end-of-life electronic displays while respecting relevant directives. [ABSTRACT FROM AUTHOR]

Nowadays there are several technologies used for flat panel displays (FPDs) and the development of FPDs with enhanced energy efficiency and improved display quality is strongly required. Field emission displays (FEDs) have been considered as one of the most promising next generation flat panel display technologies due to their excellent display performance and low energy consumption. For the development of FEDs, phosphors are irreplaceable components. In the past decade, the study of highly efficient low-voltage cathodoluminescent materials, namely FED phosphors, has become the focus of enhancing energy efficiency and realizing high-quality displays. This review summaries the recent progress in the chemical synthesis and improvement of novel, rare-earth and transition metal ions activated inorganic cathodoluminescent materials in powder and thin film forms. The discussion is focused on the modification of morphology, size, surface, composition and conductivity of phosphors and the corresponding effects on their cathodoluminescent properties. Special emphases are given to the selection of host and luminescent centers, the adjustment of emission colors through doping concentration optimization, energy transfer and mono- or co-doping activator ions, the improvement of chromaticity, color stability and color gamut as well as the saturation behavior and the degradation behavior of phosphors under the excitation of a low-voltage electron beam. Finally, the research prospects and future directions of FED phosphors are discussed with recommendations to facilitate the further study of new and highly efficient low-voltage cathodoluminescent materials. [ABSTRACT FROM AUTHOR]

Nearly all-flat panel video display monitors have luminance and color variations as the angle of view vary from the monitor’s perpendicular. The objective of this study was to measure the shift in hue and luminance of a simulated tiled monitor display at different viewing angles. The perceptibility experiment was carried out using three reference colors and 12 vectors heading towards the blue-green region of the L∗a∗b∗color space. The reference colors used were white, skin-tone, and green. A uniform reference color was presented in three of the four quadrants on a CRT monitor and one quadrant changed color in the direction of the sampled vector. An adaptive, four alternate forced choice procedure was employed to determine thresholds for each of the three reference colors. Across the three reference colors, the thresholds were at least 20% lower than the conventional one ΔEL∗a∗b∗unit used for calibrating monitors. Color difference thresholds were lowest for the blue-green region of the color space. Our results suggest that a one ΔEL∗a∗b∗uniformity criterion typically used for calibrating monitors is too lenient for tiled displays. [ABSTRACT FROM PUBLISHER]

Liquid crystal displays (LCD) are currently replacing the previously dominant cathode ray tubes (CRT) in most vision science applications. While the properties of the CRT technology are widely known among vision scientists, the photometric and temporal properties of LCDs are unfamiliar to many practitioners. We provide the essential theory, present measurements to assess the temporal properties of different LCD panel types, and identify the main determinants of the photometric output. Our measurements demonstrate that the specifications of the manufacturers are insufficient for proper display selection and control for most purposes. Furthermore, we show how several novel display technologies developed to improve fast transitions or the appearance of moving objects may be accompanied by side-effects in some areas of vision research. Finally, we unveil a number of surprising technical deficiencies. The use of LCDs may cause problems in several areas in vision science. Aside from the well-known issue of motion blur, the main problems are the lack of reliable and precise onsets and offsets of displayed stimuli, several undesirable and uncontrolled components of the photometric output, and input lags which make LCDs problematic for real-time applications. As a result, LCDs require extensive individual measurements prior to applications in vision science. [ABSTRACT FROM AUTHOR]

Background: In visual psychophysics, precise display timing, particularly for brief stimulus presentations, is often required. The aim of this study was to systematically review the commonly applied methods for the computation of stimulus durations in psychophysical experiments and to contrast them with the true luminance signals of stimuli on computer displays. Methodology/Principal Findings: In a first step, we systematically scanned the citation index Web of Science for studies with experiments with stimulus presentations for brief durations. Articles which appeared between 2003 and 2009 in three different journals were taken into account if they contained experiments with stimuli presented for less than 50 milliseconds. The 79 articles that matched these criteria were reviewed for their method of calculating stimulus durations. For those 75 studies where the method was either given or could be inferred, stimulus durations were calculated by the sum of frames (SOF) method. In a second step, we describe the luminance signal properties of the two monitor technologies which were used in the reviewed studies, namely cathode ray tube (CRT) and liquid crystal display (LCD) monitors. We show that SOF is inappropriate for brief stimulus presentations on both of these technologies. In extreme cases, SOF specifications and true stimulus durations are even unrelated. Furthermore, the luminance signals of the two monitor technologies are so fundamentally different that the duration of briefly presented stimuli cannot be calculated by a single method for both technologies. Statistics over stimulus durations given in the reviewed studies are discussed with respect to different duration calculation methods. Conclusions/Significance: The SOF method for duration specification which was clearly dominating in the reviewed studies leads to serious misspecifications particularly for brief stimulus presentations. We strongly discourage its use for brief stimulus presentations on CRT and LCD monitors. [ABSTRACT FROM AUTHOR]

Abstract: Display devices such as cathode-ray tube (CRT) televisions and computer monitors are known to contain toxic substances and have consequently been banned from disposal in landfills in the State of California and elsewhere. New types of flat panel display (FPD) devices, millions of which are now purchased each year, also contain toxic substances, but have not previously been systematically studied and compared to assess the potential impact that could result from their ultimate disposal. In the current work, the focus is on the evaluation of end-of-life toxicity potential from the heavy metal content in select FPD devices with the intent to inform material selection and design-for-environment (DfE) decisions. Specifically, the metals antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, mercury, molybdenum, nickel, selenium, silver, vanadium, and zinc in plasma TVs, LCD (liquid crystal display) TVs, LCD computer monitors and laptop computers are considered. The human health and ecotoxicity potentials are evaluated through a life cycle assessment perspective by combining data on the respective heavy metal contents, the characterization factors in the U.S. EPA Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI), and a pathway and impact model. Principal contributors to the toxicity potentials are lead, arsenic, copper, and mercury. Although the heavy metal content in newer flat panel display devices creates less human health toxicity potential than that in CRTs, for ecological toxicity, the new devices are worse, especially because of the mercury in LCD TVs and the copper in plasma TVs. [Copyright &y& Elsevier]

This paper describes the history and science behind the development of modern flat-panel displays, and assesses future trends. Electronic displays are an important feature of modern life. For many years the cathode ray tube, an engineering marvel, was universal, but its shape was cumbersome and its operating voltage too high. The need for a flat-panel display, working at a low voltage, became imperative, and much research has been applied to this need. Any versatile flat-panel display will exploit an electro-optical effect, a transparent conductor and an addressing system to deliver data locally. The first need is to convert an electrical signal into a visible change. Two methods are available, the first giving emission of light, the second modulating ambient illumination. The most useful light-emitting media are semiconductors, historically exploiting III–V or II–VI compounds, but more recently organic or polymer semiconductors. Another possible effect uses gas plasma discharges. The modulating, or subtractive, effects that have been studied include liquid crystals, electrophoresis, electrowetting and electrochromism. A transparent conductor makes it possible to apply a voltage to an extended area while observing the results. The design is a compromise, since the free electrons that carry current also absorb light. The first materials used were metals, but some semiconductors, when heavily doped, give a better balance, with high transmission for a low resistance. Delivering data unambiguously to a million or so picture elements across the display area is no easy task. The preferred solution is an amorphous silicon thin-film transistor deposited at each cross-point in an X–Y matrix. Success in these endeavours has led to many applications for flat-panel displays, including television, flexible displays, electronic paper, electronic books and advertising signs. [ABSTRACT FROM AUTHOR]

A new cost effective zero-voltage (ZVS) and zero-current switching (ZCS) current-fed energy-recovery display driver for a plasma display panel (PDP) is proposed. It features a simpler structure, less mass, and lower cost of production. Furthermore, since all power switches are turned on or off under ZVS or ZCS, it has several favorable advantages such as an improved electromagnetic interference, low switching losses, and reduced burden on the cooling system. Particularly, since the current source built in the inductor can compensate the large gas-discharge current, main inverter switches have the reduced current stress and turn-on timing margin. Therefore, the undesirable voltage notch problem caused by the improperly controlled gate signal can be solved, which enables the panel to light at lower voltage such as 143 V compared with about 165 V of the prior circuit. To confirm the operation, validity, and features of the proposed circuit, experimental results from a prototype built with a 6-in test PDP are presented. [ABSTRACT FROM AUTHOR]

Although the selective ramp reset waveform having one reset period during one television (TV)-field has a higher contrast ratio than the conventional ramp reset waveform with eight reset periods, the address discharge using the selective ramp reset waveform in a stripe barrier rib is severely influenced by the crosstalk. This problem of crosstalk among the cells constitutes the main obstacle to the development of high-resolution alternating current plasma display panels (AC-PDPs). In this paper, a new driving waveform is proposed, which renders the address discharge stable by decreasing the crosstalk, in addition to reducing the background luminance. In order to compare the address discharge stability of the proposed waveform with that of the conventional ramp reset waveform, we investigated the address discharge time lag through the photo-waveform measurement of address discharge for three waveforms and measured the dark room contrast ratio. As shown in the results, without decreasing the contrast ratio or the change of the panel structure, the address discharge time lag was considerably improved by the proposed waveform. [ABSTRACT FROM AUTHOR]

Focuses on the impact of major flat panel technologies on the cathode-ray tube (CRT) monitor markets. Plasma display panels; Electroluminescent displays; Field emission displays; Trends in the sales of flat panels versus CRT monitors.

The article focuses on the shift of cathode ray tube (CRT) to liquid crystal display (LCD) regarding on how the culture perceives the technology in the U.S. Researchers has been using the CRT already as an instrumentation and as the display technology radar. On the other hand, LCD has been applied to calculators and printers, as computers became smaller and more portable. Furthermore, despite their popularity, LCD were inferior to CRT in terms of contrast ratio, color, response time, and viewing angle.

States that flat panel or liquid crystal display (LCD) monitors will replace cathode ray tubes by 2005, according to Nikkei Microdevices. Growth expectations from the LCD market; Projection of Japanese and Korean suppliers for the LCD monitor market; Status of the flat panel television.

Discusses the Cleveland, Ohio-based Freedonia Group report "Flat Panel & CRT Display Materials: World Markets". Forecast for growth to $21,720 million in 2008; Coatings and plastic films segment as fastest growing one for this application; Sales forecast of $5,600 million in 2008; Demand for flat-panel displays.