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Field-emission Display
A field-emission display (FED) is a flat panel display technology that uses large-area field electron emission sources to provide electrons that strike colored phosphor to produce a color image. In a general sense, an FED consists of a matrix of cathode-ray tubes, each tube producing a single sub-pixel, grouped in threes to form red-green-blue (RGB) pixels. FEDs combine the advantages of CRTs, namely their high contrast levels and very fast response times, with the packaging advantages of LCD and other flat-panel technologies. They also offer the possibility of requiring less power, about half that of an LCD system. FEDs can also be made transparent. Sony was the major proponent of the FED design and put considerable research and development effort into the system during the 2000s, planning mass production in 2009. Sony's FED efforts started winding down in 2009, as LCD became the dominant flat-panel technology. In January 2010, AU Optronics announced that it acquired essential ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dead Pixel
A defective pixel or a dead pixel is a pixel on a liquid crystal display (LCD) that is not functioning properly. The International Organization for Standardization, ISO standard ISO 13406-2 distinguishes between three different types of defective pixels, while hardware companies tend to have further distinguishing types.Apple Technician Training Similar defects can also occur in charge-coupled device (CCD) and CMOS image sensors in digital cameras. In these devices, defective pixels fail to ''sense'' light levels correctly, whereas defective pixels in LCDs fail to ''reproduce'' light levels correctly. Types Dark dot defect A dark dot defect is usually caused by a transistor in the transparent electrode layer that is stuck "on" for TFT LCD#TN, TN panels or "off" for TFT LCD#MVA, MVA, PVA, and IPS panels. In that state, the liquid crystal material does not do any rotation so that the light from the backlight does not pass through the Red green blue, RGB layer of the display. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molybdenum
Molybdenum is a chemical element; it has Symbol (chemistry), symbol Mo (from Neo-Latin ''molybdaenum'') and atomic number 42. The name derived from Ancient Greek ', meaning lead, since its ores were confused with lead ores. Molybdenum minerals have been known throughout history, but the element was discovered (in the sense of differentiating it as a new entity from the mineral salts of other metals) in 1778 by Carl Wilhelm Scheele. The metal was first isolated in 1781 by Peter Jacob Hjelm. Molybdenum does not occur naturally as a Native metal, free metal on Earth; in its minerals, it is found only in oxidation state, oxidized states. The free element, a silvery metal with a grey cast, has the List of elements by melting point, sixth-highest melting point of any element. It readily forms hard, stable carbides in alloys, and for this reason most of the world production of the element (about 80%) is used in steel alloys, including high-strength alloys and superalloys. Most molybdenum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Screen-printing
Screen printing is a printing technique where a mesh is used to transfer ink (or dye) onto a Substrate (printing), substrate, except in areas made impermeable to the ink by a blocking stencil. A blade or squeegee is moved across the screen in a "flood stroke" to fill the open mesh apertures with ink, and a reverse stroke then causes the screen to touch the substrate momentarily along a line of contact. This causes the ink to wet the substrate and be pulled out of the mesh apertures as the screen springs back after the blade has passed. One colour is printed at a time, so several screens can be used to produce a multi-coloured image or design. Traditionally, silk was used in the process. Currently, synthetic threads are commonly used. The most popular mesh in general use is made of polyester. There are special-use mesh materials of nylon and stainless steel available to the screen-printer. There are also different types of mesh size which will determine the outcome and look o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inkjet
Inkjet printing is a type of printer (computing), computer printing that recreates a digital image by propelling droplets of ink onto paper or plastic substrates. Inkjet printers were the most commonly used type of printer in 2008, and range from small inexpensive consumer models to expensive professional machines. By 2019, laser printing, laser printers outsold inkjet printers by nearly a 2:1 ratio, 9.6% vs 5.1% of all computer peripherals. The concept of inkjet printing originated in the 20th century, and the technology was first extensively developed in the early 1950s. While working at Canon Inc., Canon in Japan, Ichiro Endo suggested the idea for a "bubble jet" printer, while around the same time Jon Vaught at Hewlett-Packard (HP) was developing a similar idea. In the late 1970s, inkjet printers that could Digital printing, reproduce digital images generated by computers were developed, mainly by Epson, HP and Canon. In the worldwide consumer market, four manufacturers ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palladium Oxide
Palladium(II) oxide is the inorganic compound of formula Pd O. It is the only well characterised oxide of palladium. It is prepared by treating the metal with oxygen. Above about 900 °C, the oxide reverts to palladium metal and oxygen gas. It is not attacked by acids. Structure The structure of PdO is tetragonal (''P''42/''mmc'') ''a'' = 3.044, ''c'' = 5.328 Å. The Pd atoms are square planar as expected for a d8 metal ion and the oxygen atoms are approximately tetrahedral. The closest Pd–Pd distance is 3.044 Å and is almost within the range which can be considered a bonding distance. Preparation PdO is often obtained as a poorly defined material that is generated for applications as a catalyst. Palladium oxide is prepared by heating palladium sponge metal in oxygen at 350 °C. : The oxide is obtained as a black powder. The oxide also may be prepared specially for catalytic use by heating variously a mixture of palladium(II) chloride and potassium nitrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OLED
An organic light-emitting diode (OLED), also known as organic electroluminescent (organic EL) diode, is a type of light-emitting diode (LED) in which the emissive electroluminescent layer is an organic compound film that emits light in response to an electric current. This organic layer is situated between two electrodes; typically, at least one of these electrodes is transparent. OLEDs are used to create digital displays in devices such as television screens, computer monitors, and portable systems such as smartphones and handheld game consoles. A major area of research is the development of white OLED devices for use in solid-state lighting applications. There are two main families of OLED: those based on small molecules and those employing polymers. Adding mobile ions to an OLED creates a light-emitting electrochemical cell (LEC) which has a slightly different mode of operation. An OLED display can be driven with a passive-matrix (PMOLED) or active-matrix ( AMOLED) c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active-matrix OLED
AMOLED (active-matrix organic light-emitting diode; ) is a type of OLED display device technology. OLED describes a specific type of thin-film-display technology in which organic compounds form the electroluminescent material, and active matrix refers to the technology behind the addressing of pixels. Since 2007, AMOLED technology has been used among mobile phones, media players, TVs and digital cameras, and the current progress over this technology is in lower power usage, lower cost, better resolution and specifically for larger screen (e.g. 8k screens). Design An AMOLED display consists of an active matrix of OLED pixels generating light (luminescence) upon electrical activation that have been deposited or integrated onto a thin-film transistor (TFT) array, which functions as a series of switches to control the current flowing to each individual pixel. Typically, this continuous current flow is controlled by at least two TFTs at each pixel (to trigger the luminescence), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thin-film Transistor
A thin-film transistor (TFT) is a special type of field-effect transistor (FET) where the transistor is made by thin film deposition. TFTs are grown on a supporting (but non-conducting) substrate, such as glass. This differs from the conventional bulk metal-oxide-semiconductor field-effect transistor (MOSFET), where the semiconductor material typically ''is'' the substrate, such as a silicon wafer. The traditional application of TFTs is in TFT liquid-crystal displays. Design and manufacture TFTs can be fabricated with a wide variety of semiconductor materials. Because it is naturally abundant and well understood, amorphous or polycrystalline silicon were (and still are) used as the semiconductor layer. However, because of the low mobility of amorphous silicon and the large device-to-device variations found in polycrystalline silicon, other materials have been studied for use in TFTs. These include cadmium selenide, metal oxides such as indium gallium zinc oxide (IGZO) or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescent Lamp
A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, to produce ultraviolet and make a phosphor coating in the lamp glow. Fluorescent lamps convert electrical energy into visible light much more efficiently than Incandescent light bulb, incandescent lamps, but are less efficient than most LED lamps. The typical luminous efficacy of fluorescent lamps is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output (e.g. the luminous efficacy of an incandescent lamp may only be 16 lm/W). Fluorescent lamp fixtures are more costly than incandescent lamps because, among other things, they require a electrical ballast, ballast to regulate Electric current, current through the lamp, but the initial cost is offset by a much lower running cost. Compact fluorescent lamps (CFL) made in the same sizes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold-cathode
A cold cathode is a cathode that is not electrically heated by a filament.A negatively charged electrode emits electrons or is the positively charged terminal. For more, see field emission. A cathode may be considered "cold" if it emits more electrons than can be supplied by thermionic emission alone. It is used in gas-discharge lamps, such as neon lamps, discharge tubes, and some types of vacuum tube. The other type of cathode is a hot cathode, which is heated by electric current passing through a filament. A cold cathode does not necessarily operate at a low temperature: it is often heated to its operating temperature by other methods, such as the current passing from the cathode into the gas. Cold-cathode devices A cold-cathode vacuum tube does not rely on external heating of an electrode to provide thermionic emission of electrons. Early cold-cathode devices included the Geissler tube and Plucker tube, and early cathode-ray tubes. Study of the phenomena in these d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
