1.
User interface
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The user interface, in the industrial design field of human–computer interaction, is the space where interactions between humans and machines occur. Examples of this concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machinery operator controls. The design considerations applicable when creating user interfaces are related to or involve such disciplines as ergonomics and psychology. Generally, the goal of user interface design is to produce a user interface makes it easy, efficient. This generally means that the needs to provide minimal input to achieve the desired output. Other terms for user interface are man–machine interface and when the machine in question is a computer human–computer interface, the user interface or human–machine interface is the part of the machine that handles the human–machine interaction. Membrane switches, rubber keypads and touchscreens are examples of the part of the Human Machine Interface which we can see. In complex systems, the interface is typically computerized. The term human–computer interface refers to this kind of system, in the context of computing the term typically extends as well to the software dedicated to control the physical elements used for human-computer interaction. The engineering of the interfaces is enhanced by considering ergonomics. The corresponding disciplines are human factors engineering and usability engineering, which is part of systems engineering, tools used for incorporating human factors in the interface design are developed based on knowledge of computer science, such as computer graphics, operating systems, programming languages. Nowadays, we use the graphical user interface for human–machine interface on computers. There is a difference between a user interface and an interface or a human–machine interface. A human-machine interface is typically local to one machine or piece of equipment, an operator interface is the interface method by which multiple equipment that are linked by a host control system is accessed or controlled. The system may expose several user interfaces to serve different kinds of users, for example, a computerized library database might provide two user interfaces, one for library patrons and the other for library personnel. The user interface of a system, a vehicle or an industrial installation is sometimes referred to as the human–machine interface. HMI is a modification of the original term MMI, in practice, the abbreviation MMI is still frequently used although some may claim that MMI stands for something different now. Another abbreviation is HCI, but is commonly used for human–computer interaction
2.
Cathode ray tube
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The cathode ray tube is a vacuum tube that contains one or more electron guns and a phosphorescent screen, and is used to display images. It modulates, accelerates, and deflects electron beam onto the screen to create the images, the images may represent electrical waveforms, pictures, radar targets, or others. CRTs have also used as memory devices, in which case the visible light emitted from the fluorescent material is not intended to have significant meaning to a visual observer. In television sets and computer monitors, the front area of the tube is scanned repetitively and systematically in a fixed pattern called a raster. An image is produced by controlling the intensity of each of the three beams, one for each additive primary color with a video signal as a reference. A CRT is constructed from an envelope which is large, deep, fairly heavy. The interior of a CRT is evacuated to approximately 0.01 Pa to 133 nPa. evacuation being necessary to facilitate the flight of electrons from the gun to the tubes face. That it is evacuated makes handling an intact CRT potentially dangerous due to the risk of breaking the tube and causing a violent implosion that can hurl shards of glass at great velocity. As a matter of safety, the face is made of thick lead glass so as to be highly shatter-resistant and to block most X-ray emissions. Flat panel displays can also be made in large sizes, whereas 38 to 40 was about the largest size of a CRT television, flat panels are available in 60. Cathode rays were discovered by Johann Hittorf in 1869 in primitive Crookes tubes and he observed that some unknown rays were emitted from the cathode which could cast shadows on the glowing wall of the tube, indicating the rays were traveling in straight lines. In 1890, Arthur Schuster demonstrated cathode rays could be deflected by electric fields, the earliest version of the CRT was known as the Braun tube, invented by the German physicist Ferdinand Braun in 1897. It was a diode, a modification of the Crookes tube with a phosphor-coated screen. In 1907, Russian scientist Boris Rosing used a CRT in the end of an experimental video signal to form a picture. He managed to display simple geometric shapes onto the screen, which marked the first time that CRT technology was used for what is now known as television. The first cathode ray tube to use a hot cathode was developed by John B. Johnson and Harry Weiner Weinhart of Western Electric and it was named by inventor Vladimir K. Zworykin in 1929. RCA was granted a trademark for the term in 1932, it released the term to the public domain in 1950. The first commercially made electronic television sets with cathode ray tubes were manufactured by Telefunken in Germany in 1934, in oscilloscope CRTs, electrostatic deflection is used, rather than the magnetic deflection commonly used with television and other large CRTs
3.
Cathode ray
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Cathode rays are streams of electrons observed in vacuum tubes. They were first observed in 1869 by German physicist Johann Hittorf, electrons were discovered as the constituents of cathode rays. In 1897 British physicist J. J. Thomson showed the rays were composed of a previously unknown negatively charged particle, Cathode ray tubes use a focused beam of electrons deflected by electric or magnetic fields to create the image in a classic television set. Cathode rays are made up of charged particles. Cathode rays are so named because they are emitted by the electrode, or cathode. This contrasts with cations, which are charged and go — Greek ἰόν — toward a cathode in solution. To release electrons into the tube, they first must be detached from the atoms of the cathode, modern vacuum tubes use thermionic emission, in which the cathode is made of a thin wire filament which is heated by a separate electric current passing through it. The increased random heat motion of the filament knocks electrons out at the surface of the filament, since the electrons have a negative charge, they are repelled by the cathode and attracted to the anode. They travel in straight lines through the empty tube, the voltage applied between the electrodes accelerates these low mass particles to high velocities. Researchers noticed that objects placed in the tube in front of the cathode could cast a shadow on the glowing wall, and realized that something must be travelling in straight lines from the cathode. After the electrons reach the anode, they travel through the wire to the power supply and back to the cathode. The current in a beam of cathode rays through a tube can be controlled by passing it through a screen of wires to which a small voltage is applied. The electric field of the wires deflects some of the electrons, thus a small voltage on the grid can be made to control a much larger voltage on the anode. This is the used in vacuum tubes to amplify electrical signals. These are used in cathode ray tubes, found in televisions and computer monitors, after the 1654 invention of the vacuum pump by Otto von Guericke, physicists began to experiment with passing high voltage electricity through rarefied air. In 1705, it was noted that electrostatic generator sparks travel a distance through low pressure air than through atmospheric pressure air. In 1838, Michael Faraday passed a current through an air filled glass tube and noticed a strange light arc with its beginning at the cathode. In 1857, German physicist and glassblower Heinrich Geissler sucked even more air out with a pump, to a pressure of around 10−3 atm and found that, instead of an arc
4.
Monochrome
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Monochrome describes paintings, drawings, design, or photographs in one color or values of one color. A monochromatic object or image reflects colors in shades of limited colors or hues, images using only shades of grey are called grayscale or black-and-white. However, scientifically speaking, monochromatic light refers to light of a narrow band of wavelengths. In computing, monochrome has two meanings, it may mean having only one color which is either on or off, a monochrome computer display is able to display only a single color, often green, amber, red or white, and often also shades of that color. In film photography, monochrome is typically the use of black-and-white film, originally, all photography was done in monochrome. Although color photography was possible even in the late 19th century, easily used color films, if the red channel is eliminated and the green and blue combined then the effect will be similar to that of orthochromatic film or the use of a cyan filter on panchromatic film. The selection of weighting thus allows a range of artistic expression in the final monochromatic image. For production of an image the original color stereogram source may first be reduced to monochrome in order to simplify the rendering of the image. This is sometimes required in cases where an image would render in a confusing manner given the colors and patterns present in the source image. In physics, monochromatic light is electromagnetic radiation of a single frequency, even very controlled sources such as lasers operate in a range of frequencies. In practice, filtered light, diffraction grating separated light and laser light are all referred to as monochromatic. Often light sources can be compared and one be labeled as “more monochromatic”
5.
RGB color model
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The RGB color model is an additive color model in which red, green and blue light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three primary colors, red, green and blue. Before the electronic age, the RGB color model already had a theory behind it. Thus an RGB value does not define the same color across devices without some kind of color management, typical RGB input devices are color TV and video cameras, image scanners, video games, and digital cameras. Typical RGB output devices are TV sets of technologies, computer and mobile phone displays, video projectors, multicolor LED displays. Color printers, on the hand are not RGB devices. This article discusses concepts common to all the different color spaces that use the RGB color model, to form a color with RGB, three light beams must be superimposed. Each of the three beams is called a component of color, and each of them can have an arbitrary intensity, from fully off to fully on. The RGB color model is additive in the sense that the three beams are added together, and their light spectra add, wavelength for wavelength. This is essentially opposite to the color model that applies to paints, inks, dyes. When the intensities for all the components are the same, the result is a shade of gray, darker or lighter depending on the intensity. When the intensities are different, the result is a colorized hue, a secondary color is formed by the sum of two primary colors of equal intensity, cyan is green+blue, magenta is red+blue, and yellow is red+green. The RGB color model itself does not define what is meant by red, green and blue colorimetrically, and so the results of mixing them are not specified as absolute, but relative to the primary colors. When the exact chromaticities of the red, green and blue primaries are defined, the normal three kinds of light-sensitive photoreceptor cells in the human eye respond most to yellow, green, and violet light. As an example, suppose that light in the range of wavelengths enters the eye. Light of these wavelengths would activate both the medium and long wavelength cones of the retina, but not equally—the long-wavelength cells will respond more, the difference in the response can be detected by the brain, and this difference is the basis of our perception of orange. Thus, the appearance of an object results from light from the object entering our eye and stimulating the different cones simultaneously. The first experiments with RGB in early color photography were made in 1861 by Maxwell himself, to reproduce the color photograph, three matching projections over a screen in a dark room were necessary
6.
OLED
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An organic light-emitting diode is a light-emitting diode in which the emissive electroluminescent layer is a film of organic compound that emits light in response to an electric current. This layer of organic semiconductor 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, portable systems such as mobile phones, handheld game consoles and PDAs. A major area of research is the development of white OLED devices for use in lighting applications. There are two families of OLED, those based on small molecules and those employing polymers. Adding mobile ions to an OLED creates an electrochemical cell which has a slightly different mode of operation. OLED displays can use either passive-matrix or active-matrix addressing schemes, an OLED display works without a backlight, thus, it can display deep black levels and can be thinner and lighter than a liquid crystal display. In low ambient light conditions, an OLED screen can achieve a higher contrast ratio than an LCD, andré Bernanose and co-workers at the Nancy-Université in France made the first observations of electroluminescence in organic materials in the early 1950s. They applied high alternating voltages in air to such as acridine orange. The proposed mechanism was either direct excitation of the dye molecules or excitation of electrons, in 1960 Martin Pope and some of his co-workers at New York University developed ohmic dark-injecting electrode contacts to organic crystals. They further described the energetic requirements for hole and electron injecting electrode contacts. These contacts are the basis of charge injection in all modern OLED devices, the proposed mechanism was field-accelerated electron excitation of molecular fluorescence. Also in 1965, W. Helfrich and W. G and their proposed mechanism involved electronic excitation at the contacts between the graphite particles and the anthracene molecules. Roger Partridge made the first observation of electroluminescence from polymer films at the National Physical Laboratory in the United Kingdom, the device consisted of a film of poly up to 2.2 micrometers thick located between two charge injecting electrodes. The results of the project were patented in 1975 and published in 1983, hong Kong-born American physical chemist Ching W. Tang and his co-worker Steven Van Slyke at Eastman Kodak built the first practical OLED device in 1987. This was a revolution for the technology, Universal Display Corporation holds the majority of patents concerning the commercialization of OLEDs. A typical OLED is composed of a layer of organic materials situated between two electrodes, the anode and cathode, all deposited on a substrate, the organic molecules are electrically conductive as a result of delocalization of pi electrons caused by conjugation over part or all of the molecule. These materials have conductivity ranging from insulators to conductors, and are therefore considered organic semiconductors. The highest occupied and lowest unoccupied molecular orbitals of organic semiconductors are analogous to the valence, originally, the most basic polymer OLEDs consisted of a single organic layer
7.
Liquid-crystal display
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A liquid-crystal display is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals. Liquid crystals do not emit light directly, instead using a backlight or reflector to produce images in color or monochrome and they use the same basic technology, except that arbitrary images are made up of a large number of small pixels, while other displays have larger elements. LCDs are used in a range of applications including computer monitors, televisions, instrument panels, aircraft cockpit displays. Small LCD screens are common in consumer devices such as digital cameras, watches, calculators. LCD screens are used on consumer electronics products such as DVD players, video game devices. LCD screens have replaced heavy, bulky cathode ray tube displays in all applications. LCD screens are available in a range of screen sizes than CRT and plasma displays, with LCD screens available in sizes ranging from tiny digital watches to huge. Since LCD screens do not use phosphors, they do not suffer image burn-in when an image is displayed on a screen for a long time. LCDs are, however, susceptible to image persistence, the LCD screen is more energy-efficient and can be disposed of more safely than a CRT can. Its low electrical power consumption enables it to be used in battery-powered electronic equipment more efficiently than CRTs can be, by 2008, annual sales of televisions with LCD screens exceeded sales of CRT units worldwide, and the CRT became obsolete for most purposes. Without the liquid crystal between the filters, light passing through the first filter would be blocked by the second polarizer. Before an electric field is applied, the orientation of the molecules is determined by the alignment at the surfaces of electrodes. In a twisted nematic device, the surface alignment directions at the two electrodes are perpendicular to other, and so the molecules arrange themselves in a helical structure. This induces the rotation of the polarization of the incident light, and this light will then be mainly polarized perpendicular to the second filter, and thus be blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, color LCD systems use the same technique, with color filters used to generate red, green, and blue pixels. The optical effect of a TN device in the state is far less dependent on variations in the device thickness than that in the voltage-off state. Because of this, TN displays with low content and no backlighting are usually operated between crossed polarizers such that they appear bright with no voltage. When no image is displayed, different arrangements are used, for this purpose, TN LCDs are operated between parallel polarizers, whereas IPS LCDs feature crossed polarizers
8.
Shades of orange
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In optics, orange has a wavelength between approximately 585 and 620 nm and a hue of 30° in HSV color space. In the RGB color space it is a tertiary color numerically halfway between gamma-compressed red and yellow, as can be seen in the RGB color wheel, the complementary color of orange is azure. Orange pigments are largely in the ochre or cadmium families, varieties of the color orange may differ in hue, chroma or lightness, or in two or three of these qualities. Variations in value are also called tints and shades, a tint being an orange or other hue mixed with white, a large selection of these various colors is shown below. At right is the orange, also known as color wheel orange. This is the tone of orange that is a pure chroma on the HSV color wheel, the complementary color of orange is azure. At right is the web color called orange and it is defined in CSS as the hex triplet FFA500. The web color called dark orange is at the right, at right is displayed the color that is called orange in Pantone. The source of color is the Pantone Textile Paper eXtended color list. At right is displayed the color that is called orange by Crayola, orange was one of the original colors formulated by Crayola in 1903. Displayed at right is the web color papaya whip, a tint of orange. Papaya whip is a representation of the color that would result if mashed papayas were blended with ice cream, whipped cream. At right is displayed the color peach, the first recorded use of peach as a color name in English was in 1588. Displayed at right is the light orange. This color was formulated for Crayola colored pencils, at right is displayed the color apricot. Apricot has been in use as a name since 1851. Displayed at right is the color melon and this color is a representation of the color of the interior flesh of a cantaloupe, the most commonly consumed melon. The first recorded use of melon as a name in English was in 1892
9.
Shades of green
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Varieties of the color green may differ in hue, chroma or lightness, or in two or three of these qualities. Variations in value are also called tints and shades, a tint being a green or other hue mixed with white, a large selection of these various colors is shown below. Green is common in nature, especially in plants, many plants are green mainly because of a complex chemical known as chlorophyll which is involved in photosynthesis. Many shades of green have been named after plants or are related to plants, due to varying ratios of chlorophylls, the plant kingdom exhibits many shades of green in both hue and value. Artichoke is a color that is a representation of the color of a raw fresh uncooked artichoke, another name for this color is artichoke green. The first recorded use of green as a color name in English was in 1905. This is the color called green in Pantone. The source is Pantone 18-0125 TPX Asparagus is a tone of green that is named after the vegetable, Crayola created this color in 1993 as one of the 16 to be named in the Name the Color Contest. It is also the color of a wild asparagus plant blowing in the wind of the 1949 classic film Sands of Iwo Jima, another name for this color is asparagus green. The first recorded use of green as a color name in English was in 1805. Avocado is a color that is a representation of the color of the surface of an avocado. The color avocado is a dark yellow-green color, avocado was a common color for metal surfaces, as well as the color harvest gold, during the whole decade of the 1970s. They were both also popular colors for shag carpets, both colors went out of style by the early 1980s. Dark green is a shade of green. A different shade of green has been designated as green for certain computer uses. Fern green is a color that resembles ferns, a Crayola crayon named fern was created in 1998, which is a lighter shade of the top color shown on the right. The first recorded use of green as a color name in English was in 1902. Forest green refers to a green color said to resemble the color of the trees, the first recorded use of forest green as the name of a color in the English language was in 1810
10.
Indigo
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Indigo is a deep and rich color close to the color wheel blue, as well as to some variants of ultramarine. The color indigo is named after the indigo dye derived from the plant Indigofera tinctoria, the first known recorded use of indigo as a color name in English was in 1289. Species of Indigofera were cultivated in Peru, India, East Asia, the earliest direct evidence for the use of indigo dates to around 4000 BCE and comes from Huaca Prieta, in contemporary Peru. Pliny mentions India as the source of the dye, imported in small quantities via the Silk Road, the Greek term for the dye was Ἰνδικὸν φάρμακον, which, adopted to Latin as indicum and via Portuguese gave rise to the modern word indigo. El Salvador has lately been the biggest producer of indigo, Indigo was actually a plant that got its name because it came from the Indus Valley, discovered some 5,000 years ago, where it was called nila, meaning dark blue. And by the 7th Century BC, people starting using the plant as a dye — the Mesopotamians were even carving out recipes for making indigo dye onto clay tablets for record-keeping. By 1289, knowledge of the dye made its way to Europe, but it wasn’t until 1640 when demand started to pick up for indigo. Spanish explorers discovered an American species of Indigo and began to cultivate the product in Guatemala, the English and French subsequently began to encourage indigo cultivation in their colonies in the West Indies. Indigo dye could be made from two different types of plants — the indigo plant, which produced the best results, the British were producing indigo with woad, a plant that yielded a lesser quality dye, but a plant they could grow. They even tried to hold their monopoly on indigo dye by managing to ban the indigo plant for years, but eventually the British began to focus on tea and other crops — and meanwhile, the French started to get their fair share of the market. The French had gone to war with Britain, so the British could hardly rely on the French for this precious blue dye, consequently, the British had to turn to their colonies in America. It was Eliza Lucas from South Carolina who figured out how to grow the indigo plant, the same indigo dye is contained in the woad plant, Isatis tinctoria, for a long time the main source of blue dye in Europe. Woad was replaced by true indigo as trade routes opened up, the Early Modern English word indigo referred to the dye, and not to the color itself, and indigo is not traditionally part of the basic color-naming system. Modern sources place indigo in the spectrum between 420 and 450 nanometers, which lies on the side of color wheel blue. However, the correspondence of this definition with colors of actual indigo dyes is disputed, isaac Newton introduced indigo as one of the seven base colors of his work. In a pivotal experiment in the history of optics, the young Newton shone a narrow beam of sunlight through a prism to produce a band of colors on the wall. He linked the seven prismatic colors to the seven notes of a major scale, as shown in his color wheel, with orange. Indigo is therefore counted as one of the colors of the rainbow
