Electronics Spectra - SMS Lucknow

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SMS Institute of Technology, L ucknow Department of Electronics & Co mmunication Surface-conduction electron-emitter display (SED) Priyanka Gupta EC - III year less power than an LCD television of the same size. After considerable time and effort in the early and mid-2000s, SED efforts started winding down in 2009 as LCD became the dominant technology. SED are closely related to another developing display technology, the field emission display, or FED, differing primarily in the details of the electron emitters. Sony, the main backer of FED, has similarly backed off from their development efforts. Canon's 36" prototype SED, sho wn at the 2006 CES WORKING A surface-conduction electronemitter display (SED) is a fla t panel color television technology currently being developed by a number of companies. SED use nanoscop icscale electron emitters to energize colored phosphors and produce an image. In a general sense, a SED consists of a matrix of tiny cath ode ray tubes, each "tube" forming a s ingle sub-pixel on the screen, group ed in threes to form red-green-blue (RGB) pixels. SED combine the advantages of CRTs, namely their high con trast ratios, wide viewing angles and very fast response times, with the packaging advantages of LCD and ot her flat panel displays. They also use much A conventional cathode ray tub e (CRT) is powered by an electron gun, essentially an open-ended vacu um tube. At one end of the gun el ectrons are produced by "boiling" them off a metal filament, which re quires relatively high current. The electrons are then accelerated and focused into a fast-moving beam, flowing forward towards the screen. Electromag nets surrounding the gun end of the tube are used to steer the beam as it travels forward, allowing the beam to be scanned across the screen to produce a 2D display. When the fast-mo ving electrons strike phosphor on the back of the screen, light is produced. Color images are produced by painting the screen with spots or stripes of three colored phosphors, one each for red, green and blue (RGB). When viewed from a distance, the spots, known as "sub-pixels", blend together in the eye to produce a single colored sp ot known as a pixel. COMPARISON Liquid crystal display television The primary large-screen television technology being deployed in t he 2000's is the liquid crystal display televisions. SED aimed at the same market segment. LCD does not dire ctly produce light, and have to be back-lit using cold cathode fluorescent lamps (CCFL) or high-power LED. The SED produces light directly on its front surface. Scenes are lit only on those pixels that require it, and only to the amount of brightness they requ ired. Canon's 55" prototype SED offe red bright images of 450 cd/m2, 50,000:1 contrast ratios, and a response time of less than 1 ms. Canon has s tated that production versions would improve the response time to 0.2 ms and 100,000:1 contrast ratios Current generation Next generation Electroluminescent display (EL D),Vacuum fluorescent display (VFD), Light emitting diode display, Cathode ray tube (CRT),Liquid crystal display (LCD),Plasma display panel (PDP),Digital light processing (DLP),Liquid crystal on silicon (LCoS). Organic light-emitting diode (OLED),Surface-conduction electron-emitter display (SED),Field emission display (FED),Laser TV (Quantum dot laser, Liquid crystal laser), Ferro liquid display (FLD),Interferometric modulator display (iMoD), Thick-film dielectric electroluminescent (TDEL),Quantum dot display (QD-LED),Time-multiplexed optical shutter (TMOS),Telescopic pixel display (TPD),Organic light-emitting transistor (OLET),Laser phosphor display (LPD). 42 Electronics Spectra, 2010
SMS Institute of Technology, L ucknow Department of Electronics & Co mmunication E -Waste Electronic waste, E- scrap or waste Electrical and electronic equipment (WEEE) DEFINITION "Electronic waste" may be defined as all secondary computers, entertainment devic e electronics, mobile phones, and other items such as television sets and refrigerators, whether sold, donated, or discarded by their original ow ners. This definition includes used electronics which are destined for reuse, resale, salvage, recycling, or d isposal. Others define the re-usables ( working and repairable electronics ) and secondary scrap (copper, steel, etc.) to be "commodities", and reserve the term "waste" for residue or material which was represented as working or repairable but which is dumped or disposed or discarded by the buye r rather than recycled, includin g residue from reuse and recycling operations. "Electronics Waste is a waste consisting of any broken or unwanted electrical or electrical appliance." GLOBEL TRADE IS- SUES FOR E-WASTE Increased regulation of electronic waste and concern over the environmental harm which can result f rom toxic electronic waste has raised disposal costs. The regulation creates an economic disincentive to remove residues prior to export. Critics of trade in used electronics maintain that it is too easy for brokers calling themselves recyclers to export unscreened electronic waste to developing countries, such as China, India and parts of Africa, thus avoiding the expens e of removing items like bad cathode ray tubes (the processing of which is expensive and difficult). The de veloping countries are becoming big dump yards of e-waste due to their weak laws. Proponents of internatio nal trade point to the success of fair trade programs in other industries, where cooperation has led creation of sustainable jobs and can bring affordable technology in countries where repair and reuse rates are higher. In highly polluting, primitive Guiya in the Shantou region of China, Delhi and Bangalore in India as well as the Agbogbloshie site near Accra, Ghana have electronic waste processing areas. Uncontrolled burning, disassembly, and disposal can cause a variety of environmental problems such as groundwater contamination, atm o- spheric pollution, or even water pollution either by immediate dis charge or due to surface runoff (espe cially near coastal areas), as well as health problems including occupational safety and health effects among those directly involved, due to the me thods of processing the waste. Thous ands of men, women, and children are employed recycling technologies, extracting the metals, toners, and pl astics from computers and other electronic Aditya Bhardwaj EC - III year waste. Recent studies show tha t 7 out of 10 children in this region have too much lead in their blood. SOURCES OF E-WASTE ‣ IT &TELECOM Equipments ‣ Large household Appliances & Small household Appliances ‣ Consumer & Lighting Equipments ‣ Electrical & Electronics Tools ‣ Toys, Leisure & Sports Equipment ‣ Medical Devices ‣ Monitoring & Control Instruments E- WASTE MANAGEMENT Recycling: Today the electronic waste rec y- cling business is in all areas of the developed world a large and rapidly consolidating business. Electronic waste processing systems have matured in 43 Electronics Spectra, 2010
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